Abstract: A low pressure plasma or laser spray metal deposition process for the manufacture of a vacuum interrupter contact with a tailored composition gradient through the thickness of the contact.

Abstract: The present invention is directed to a four-region solid-state switching device whose topology readily links itself to light activation. Anode and cathode emitter regions of the device are disposed in the same surface of the device. Both base regions are exposed on a mesa portion disposed between the anode and cathode regions. The topology of the device is such that current flows across the device rather than through the device and light is introduced through the base regions perpendicular to the direction of current flow.

Abstract: A vacuum-type circuit interrupter is provided having a bimetallic vapor or condensing shield. The shield has a first surface consisting of a layer of a high electrically conductivity metal, as for example copper which is exposed to or faces the arcing area within the interrupter and a second layer of a superior high voltage material, as for example stainless steel which is affixed to that surface of the layer of copper away from the arcing area. The layer of stainless steel overlaps the layer of copper at the ends of the shield to an extent that allows it to be rolled over or formed to relieve electrical stresses.

Abstract: The present invention provides a method for triggering a light triggered thyristor (LT.sup.2) which method comprises using a light source to provide background excitation of carriers in at least the amplifying gate areas of the LT.sup.2 prior to triggering the device. The background excitation is of a low level and will not trigger the device or cause excessive leakage current. At the desired time a second light signal is used to trigger the LT.sup.2.

Abstract: The present invention is directed to a process for providing overvoltage protection to a thyristor and to the thyristor so protected and comprises contacting the space charge region of the forward blocking junction of the thyristor with an electrical contact when the predetermined switching voltage is reached.

Abstract: A vacuum-type circuit interrupter is provided having a vapor condensing shield which at least in the arcing area is comprised of the same two metallic components as the separable metallic electrical contacts.

Abstract: The present invention is directed to a cup type vacuum interrupter contact comprised of a holder portion and a contact portion. The holder portion is cup shaped and has a base and side walls extending vertically from the base. The contact portion is circular in configuration corresponding approximately in shape and cross-sectional area to the side walls of the holder portion and is disposed on and affixed to the rim of the side walls. The holder portion has slots extending at an angle from its base through the side walls to the rim. The holder portion is comprised of a precipitation-hardened copper alloy and the contact portion is comprised of copper.

Abstract: A method for electrically shorting a high current, low voltage, single, chloralkali, membrane, electrolytic cell of a certain configuration to permit first its removal from a system, comprised of a plurality of electrically series connected cells, for maintenance purposes and then its return to the system. The method comprises first employing an electrical jumper circuit, comprised of two sets of bus bars and a switch, to electrically short out two adjacent cells, one of which is to be removed from the system to undergo maintenance, and then to modify the circuit in situ to enable the shorted cell adjacent to the cell to be removed to be returned to the system almost immediately.

Abstract: The present invention is directed to a light-triggered thyristor having a high di/dt, high dv/dt, and high photosensitivity. The thyristor has a three-stage cathode emitter gating structure with integrated current limiting resistors. The current limiting resistors are defined by moats etched in the cathode base region. The moats also cause a "turn-on " current to flow through substantially all of the cathode base region.

Abstract: The present invention is directed to an assembly-heat sink for semiconductor fusions. The fusions are disposed within the assembly-heat sink between cylindrical metal members which both cool the fusions and facilitate making electrical contact to the fusions. Top and bottom members of the assembly-heat sink, which entirely enclose the cylindrical members and the fusions are comprised entirely of metal permitting the assembly-heat sink to be cooled from three sides. The fusions are electrically insulated from the top and bottom members of the assembly-heat sink.

Abstract: The present invention is directed to a thyristor self-protected against overvoltage by the avalanche mechanism, the protection resulting from a well cut in the top surface of the thyristor and extending through one base region of the thyristor and forming two regions of opposite conductivity type at the bottom of said well, and to the process for making the thyristor.

Abstract: The present invention is directed to a thyristor self-protected against overvoltage by the avalanche mechanism, the protection resulting from a laser scribed ring shaped groove cut in the top surface of the thyristor and extending into one base region of the thyristor whereby the forward blocking junction is contoured toward the reverse blocking junction under the ring shaped groove, and to the process for making the thyristor.

Abstract: The present invention is directed to a semiconductor device in which a wafer of semiconductor material is soldered to a graphite substrate.

Abstract: The present invention is directed to a mesa type semiconductor device, formed in a body of semiconductor material, containing at least one guard ring region. The at least one guard ring region is formed to a relatively shallow depth within the body thereby reducing the height of the mesa above the main portion of the body of semiconductor material. The resultant device is physically stronger than prior art devices.

Abstract: The present invention is directed to a process for preparing a body of polycrystalline silicon doped with aluminum comprising melting a mixture of silicon powder and aluminum powder, rapidly quenching the melt, grinding the solidified silicon-aluminum alloy and hot pressing to form a compact.

Abstract: The present invention comprises a discrete main thyristor and a discrete auxiliary thyristor contained within a single case or package member. The auxiliary thyristor is triggered by a light signal passing through an aperture in a wall of the case member. The auxiliary thyristor in turn triggers the main thyristor.

Abstract: A method for predicting certain electrical failures in a semiconductor device after long-term operation, includes the steps of measuring a predetermined parameter of the semiconductor device before and after it is exposed to a corona discharge and then comparing the two measurements.

Abstract: A common Baker Clamp includes diodes having predetermined reverse-recovery times for responding to a signal having a high frequency on the order of 100 kHz. A pair of anti-parallel diodes coupled between an input terminal and a first output terminal are each characterized by a reverse-recovery time on the order of 2.mu.s. A third diode is coupled between the input terminal and a second output terminal and is characterized by a reverse-recovery time on the order of 200 ns.

Abstract: The present invention is directed to a diffusion source for establishing a p-type conductivity region in a semiconductor device and to a method for preparing such diffusion source. The diffusion source consists of pure silicon powder diffused with a p-type impurity.

Abstract: An electronic device is provided comprising two or more discrete semiconductor devices in an electrical circuit relationship, hermetically sealed within a single case member. Electrical and thermal conductivity between the semiconductor devices and electrodes on the case member is established and maintained by the application of a compressive force to the case member. The compressive force applied to the case member is distributed to the individual semiconductor devices sealed within the case member.